Mobile phone producer HTC's research has revealed how football fans in stadiums across Europe are bringing volume and variety to the social media debate, accounting for more than a third -- 35% -- of all local tweets about each match. Four of the first matches of this season's Champions League group stage showed that fans watching at the grounds are responsible for nearly 10 times more tweets per fan than TV viewers. Big games are now familiar on Twitter feeds -- with up to 83% of fans using a second screen while watching football, and the smartphone is playing a big role in interaction with the game, nowhere more than at the match itself. Comparing conversations of fans in stadiums to tweets from the rest of the country, the study found that fans in stadiums enjoy being amateur pundits in match conversations, mentioning scorelines (24%), goals (23%) and managers (14%). The study found that Chelsea fans were the noisiest, with 129 tweets per 100 attendees. AC Milan fans had nine tweets per 100 attendees. Overall, stadium crowds in the U.K. (Stamford Bridge) and Spain (Camp Nou) were more active on social media than those in Italy (AC and Inter Milan's Stadio Giuseppe Meazza) and France (Olympique de Marseille's Stade Vélodrome), accounting for more than 88% of the social conversation between the four. The study showed that clubs also want to get in on social media. Where fans were noisiest, at Chelsea's Stamford Bridge, the team only tweeted 38 times. With a quieter social media crowd in France, Olympique de Marseille's account reached 182 tweets on matchday to offer extra content to keep fans engaged (HTC).